Many processes for the production of petrochemicals require a gaseous feed to be heated to high temperature prior to carrying out a reaction. Some examples are dehydrogenation of ethylbenzene to form styrene monomer, and dehydrogenation of propane or butane to form butenes or butadiene. A significant amount of fuel must be burned in a fired heater to generate the required temperatures for the feed gas. The excess heat in the reactor effluent may be recovered as steam. However, in many cases this energy conversion from fuel to steam is not the most economical option and it is desirable to recover as much of the heat as possible in a feed effluent heat exchanger in order to minimize the amount of fuel consumed by the process.
Conventional heat exchanger methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for systems and methods that provide for improved and more thermally efficient shell and tube heat exchangers.